Header Gaskets

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Doppleganger

Full Access Member
Joined
May 24, 2019
Posts
11,852
Reaction score
54,881
Location
OH-MI: Just like it sounds
First Name
Chris
Truck Year
1985
Truck Model
K20
Engine Size
5.7
Got ready to install my headers and realized the gaskets I had were some cheap fiber ones that came with the headers. Was wondering what you fellas used that worked. Fel-pro? Copper? etc.

I have Edelbrock E-Tec (vortec style) heads and anything I saw that looked interesting never mentioned anything vortec.

THX
 

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
1,760
Reaction score
3,787
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
Remflex is what I will be putting on my 76, have a remflex manifold gasket on my slant six in the dart and it sealed things up tight.

Only issue with them is being graphite they are fragile, for the long slender slant six gasket it took 4 tries to get one not broken in half.

My 76 previously and my 79 has those dead soft aluminum layered gaskets and those seem to work well too.
 

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
1,659
Reaction score
2,255
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
When I was a crewmember on a race team we used a thin bead of high temp silicone on both sides of gasket. Applied sealant then waited 10-15 minutes to solidify a little bit. Never had a leak issue. These were high dollar headers with a thick flange. Your millage may vairy.

Have headers on one of my personal vehicles. Always check for loose bolts once a year.
 

Dutch Rutter

Full Access Member
Joined
Aug 13, 2013
Posts
1,075
Reaction score
1,199
Location
Independence, Or
First Name
Joshua
Truck Year
1984
Truck Model
K20
Engine Size
5.7
I've posted this before around here somewhere. When I redid the 350 in my k20 I used the remflex gaskets top and bottom, then the proform wedge locking header bolts. Had great results. These were also used on a set of old flowtechs on aluminum heads, so if they could seal that they'll work really well on higher grade stuff.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,224
Reaction score
5,156
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I'll put in one more vote for Remflex... they really can't be beat. I have them on my 350 and my LS motor with headers. No leaks at all.
 

nvrenuf

Full Access Member
Joined
Jul 30, 2010
Posts
1,746
Reaction score
1,998
Location
Mobile, Al.
First Name
John
Truck Year
1991
Truck Model
K5
Engine Size
454
Header flange thickness is directly related to gasket sealing success. Thin flanges can get warped easily, thick flanges seal better for longer.

My Sanderson’s have 3/8” flanges and seal great with Permatex Ultra Black.
 

Doppleganger

Full Access Member
Joined
May 24, 2019
Posts
11,852
Reaction score
54,881
Location
OH-MI: Just like it sounds
First Name
Chris
Truck Year
1985
Truck Model
K20
Engine Size
5.7
So I call Summit - they ask me what I'm working on. I tell them I'm looking to buy a decent set of header gaskets for a SBC. Before I can tell them the PN I looked up, guy suggests....Remflex. lol So I ordered the Remflex header and collector gaskets yesterday. They are out for delivery today.

Thanks fellas!
 

TotalyHucked

Full Access Member
Joined
Feb 24, 2020
Posts
2,829
Reaction score
9,108
Location
Auburn, Georgia
First Name
Zach
Truck Year
1985
Truck Model
Sierra 1500
Engine Size
5.3
I'm now on my 3rd set of MLS gaskets with my Speed Engineering headers and they leak. 1st set lasted a long time, 2nd and 3rd leaked almost immediately. The flanges are good and thick but I guess they've warped by now. I think I'll give RemFlex a try for the next ones
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,224
Reaction score
5,156
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I'm now on my 3rd set of MLS gaskets with my Speed Engineering headers and they leak. 1st set lasted a long time, 2nd and 3rd leaked almost immediately. The flanges are good and thick but I guess they've warped by now. I think I'll give RemFlex a try for the next ones
I just put a set of the speed engineering long tubes on my suburban and the back bolt was broken off the passenger side. I couldn't get anything in there to extract it and it's getting the 6.2 put in it in a few weeks anyways, so I said screw it. Remflex gaskets and ICT billet header bolts and torqued the bolts all to the recommended remflex torque spec... zero leaks. None of the bolts have loosened up or broken either. I put the exhaust in because I figured the 6.2 wouldn't do too well with the tiny 5.3L stock exhausdt system and wow what a difference. 1-3/4" long tubes to 3" high flow cats to a single 3.5". Then a flex pipe, 3.5" resonator, and single 3.5" flowmaster 50 series Big Block muffler. Fuel trims almost immediately went to +20, so I'll need to do some tweaking on the tune to take advantage of the extra efficiency, but it has quite a bit more roar during acceleration and no resonation or excessive loudness at cruise.
 

Latest posts

Forum statistics

Threads
42,304
Posts
913,364
Members
33,800
Latest member
504SquareBody
Top